var chunkToChildrenMap = <%- _chunk_map %>;
<%- ENSURE_CHUNK_HANDLERS %>.prefetch = <%- basicFunction("chunkId, promises") %> {
  Promise.all(promises).then(<%- basicFunction("") %> {
    var chunks = chunkToChildrenMap[chunkId];
    Array.isArray(chunks) && chunks.map(<%- PREFETCH_CHUNK %>);
  });
};